Research on the characteristic map and content determination of commonly used traditional Chinese medicine decoction pieces in the Rutaceae family based on standard decoction
Chinese herbal medicines such as tangerine peel, green peel, tangerine peel, Huaju red, and bergamot belong to the citrus genus of the Rutaceae family and are commonly used in clinical practice for regulating qi. One of the green peels is the dried young fruit of Citrus reticulata Blanco and its cultivated varieties in the Rutaceae family; Four white green skin is a plant of the Rutaceae family, Orange C Peel of dried immature fruits of Retina Blanco and its cultivated varieties; Chenpi is the dried and mature fruit peel of Citrus reticulata Blanco and its cultivated varieties in the Rutaceae family; Citrus aurantium L. and its cultivated varieties are dried immature fruits of the Rutaceae plant Citrus aurantium L; Citrus grandis’ Tomentosa ‘or Citrus grandis (L.) Osbeck, a plant in the Rutaceae family, is the immature or nearly mature dried outer skin of Citrus grandis (L.) Osbeck; Buddha’s hand is the dried fruit of Citrus medica L.var. sarcodactyls Swingle, a plant in the Rutaceae family. This traditional Chinese medicine has similar effects such as regulating qi, strengthening spleen, and resolving phlegm. Its main chemical components are flavonoids such as hesperidin, neohesperidin, and naringin. At present, the commonly used traditional Chinese medicines in the Rutaceae family are mainly focused on the determination of medicinal content, fingerprint analysis, or quality research of single ingredient standard decoctions. Due to the fact that clinical preparations are often taken in the form of decoctions, granules, etc., clinical preparations have lost the microscopic and morphological identification characteristics of the original decoction pieces, that is, they cannot be inspected and identified based on the shape, size, color, surface, texture, aroma, taste, and other characteristics of the medicinal materials, which is not conducive to the quality control of clinical drugs. This study focuses on the standard decoction of citrus fruits in the Rutaceae family, including Geqingpi, Sihuaqingpi, Chenpi, Citrus aurantium, Huajuhong, and Foshou. Multiple index content determination and UPLC characteristic spectrum methods were established to investigate the differences in quality. The aim is to provide reference for the quality control of decoction pieces, intermediates, and finished products, as well as the transfer of chemical composition values during the preparation process of standard decoction and granules.

The standard decoction of traditional Chinese medicine is guided by the theory of traditional Chinese medicine and based on clinical application. It is prepared through decoction, solid-liquid separation, concentration, and freeze-drying, and is a key substance for the study of quality markers of traditional Chinese medicine. It is the material basis for measuring whether traditional Chinese medicine formula particles are basically consistent with clinical decoction. The medicinal herbs of the Citrus genus in the Rutaceae family have different focuses in clinical use. For example, Qingpi is good at soothing the liver and breaking down qi, reducing accumulation and stasis, while Chenpi, which is more mature, is good at regulating qi and strengthening the spleen, drying dampness and resolving phlegm. However, the chemical composition of the two medicinal herbs is relatively similar. Therefore, this study analyzed different Citrus genus medicinal herbs in the Rutaceae family based on standard decoctions to provide reference for clinical medication.
This study established the UPLC characteristic map and multi index content determination method for the standard decoction of Rutaceae citrus slices, and analyzed the samples of Rutaceae citrus standard decoction from different sources. The analysis of characteristic spectra shows that there are differences in the number of chromatographic peaks in the characteristic spectra of standard decoction samples from different sources of Rutaceae citrus genus. The characteristic spectra can be used to visually distinguish the six Rutaceae citrus genera. Cluster analysis and principal component analysis showed that Citrus aurantium, Citrus aurantium, and bergamot can be grouped separately. Oranges at different maturity stages (Geqingpi, Sihuaqingpi, Chenpi) have intersecting characteristics, with significant differences between different species and small differences between samples of the same species. In order to further distinguish the differences between oranges (Geqingpi, Sihuaqingpi, Chenpi) at different maturity stages, partial least squares discriminant analysis was used for analysis, which can identify and cluster the three and confirm that hesperidin, neohesperidin, Yunxiangyupi glycoside, and peak 7 are the main substances with quality differences. It is speculated that the content of the above components may be related to the maturity stage.
Based on the characteristic map, this study determined the content of seven main indicator components in standard decoction samples of different Rutaceae citrus genus. The results showed that there were significant differences in the content of the seven components among different samples, with RSD ranging from 38.97% to 91.81%. The average content of naringin in Citrus grandiflorum is higher than that in Citrus aurantium; Hesperidin can be detected in all samples except for orange infrared spectroscopy. The average content is as follows: Four flowered green peel>Chenpi>Geqingpi>Fructus Aurantii; New hesperidin can be detected in Fructus Aurantii, Fructus Aurantii, and Fructus Aurantii, with an average content of Fructus Aurantii>Fructus Aurantii>Fructus Aurantii; Hydrated hesperidin can be detected in Fructus Aurantii, Citrus reticulata, and bergamot, with an average content of Fructus Aurantii>Citrus reticulata>bergamot; Chuanchenpi extract and hesperidin can be detected in all samples except for Huajuhong and bergamot. The average content is as follows: Chenpi>Sihuaqingpi>Geqingpi>Citrus aurantium. The content determination results are consistent with the feature map results, and there are differences in both composition and content among samples of different varieties, which may be one of the reasons for their different clinical efficacy.
The UPLC characteristic map method established in this study comprehensively reflects the chemical composition of the standard decoction of Rutaceae citrus slices, and the seven characteristic components that have been assigned were determined by the same method. The analysis method is fast and simple, and the use of chemical stoichiometry analysis effectively distinguishes the commonly used standard decoction of Rutaceae citrus slices, which can provide a basis for the quality evaluation of Rutaceae citrus slice standard decoction and related preparations.